Matching Items (8)

134090-Thumbnail Image.png

A Review of the Current Understanding on Immune Cell Sensitivity to Variation in Energy Availability

Description

This study takes a broad look into the existing research on the relationship between two physiological topics, nutrition and immunity in vertebrates, specifically the mammalian and avian branches. This was

This study takes a broad look into the existing research on the relationship between two physiological topics, nutrition and immunity in vertebrates, specifically the mammalian and avian branches. This was achieved by critiquing available studies on different types of immune cells, and how variable energy availability, as well as specific pathogens, impact cell function. Notably, most studies examined individuals with compromised immune systems, which reveals an existing knowledge gap in the linkages between nutrition and immunity in healthy organisms. Links between immunity and nutrition were identified across the studies, with the three main energy molecules, carbohydrates, lipids, and proteins, implicated in functional roles as immune modulators. Stimulatory and inhibitory effects occur dependent on elevated and depleted nutrient levels, and multiple cell types are sensitive to changes in nutrient availability. Further studies should be conducted on healthy individuals of model species, as well as wildlife and other non-model species to identify and describe the effects of host nutritional status on the spread of pathogens and the implications at the population level for humans, domestic animals, and wildlife.

Contributors

Agent

Created

Date Created
  • 2017-12

133270-Thumbnail Image.png

Comparative Analysis of Immunosignatures and Serological Reactivity for Disease Profiling

Description

Blood donations today undergo extensive screening for transfusion transmitted infections (TTI) since the discovery of the first infectious agent in the early 1900s. Nucleic Acid Testing (NAT) is a serological

Blood donations today undergo extensive screening for transfusion transmitted infections (TTI) since the discovery of the first infectious agent in the early 1900s. Nucleic Acid Testing (NAT) is a serological test used widely in disease detection. NAT is known to rapidly and effectively detect pathogenic genomic material in blood by reducing the "window period" of infection. However, NAT produces false negative results for disease positive samples posing a risk of disease transmission. Therefore, NAT is used in conjunction with the Enzyme-Linked Immunosorbent Assay (ELISA) to mitigate these risks. However, the ELISA assay also poses the same risk as NAT. This study proposes immunosignaturing as an alternative serological test that may combat this risk and investigates whether it would be more effective than other standardized serological tests in disease detection. Immunosignaturing detects antibodies by utilizing a microarray of randomized peptide sequences. Immunosignaturing provides information about an individual's immune health from the pattern of reactivity of antibody-peptide binding. Unlike ELISA and NAT, immunosignaturing can be programmed to detect any disease and detect multiple diseases simultaneously. Using ELISA, NAT, and immunosignaturing, immune profiles of asymptomatic patients were constructed for 10 different classes of blood borne diseases. A pattern of infection was identified for each disease and the sensitivity and specificity of these assays were assessed relative to each other. Results indicate that immunosignaturing can be a viable diagnostic tool in blood testing. Immunosignatures demonstrated increased sensitivity and specificity compared to ELISA and NAT in discerning disease positive and negative samples within and across different classes of disease.

Contributors

Agent

Created

Date Created
  • 2018-05

HIV Stigma: A Research and Art Investigation

Description

In the years following the HIV epidemic, much has changed in the way of public health, the social epidemic of stigma has remained. It is the assertion of the authors

In the years following the HIV epidemic, much has changed in the way of public health, the social epidemic of stigma has remained. It is the assertion of the authors that stigma can be combatted through the propagation of accurate education and exposure to the lasting negative impacts of social stigma on persons living with HIV in the United States at present. Although individuals who are not apart of this community cannot truly understand the impacts of HIV-related stigma on those directly impacted by it, a sense of understanding and compassion may be elicited through the breakdown of social stigma into comprehensible components and the provision of stigma-inspired artwork. In addition to providing a background on the scientific basis of Human immunodeficiency virus and its spread, the authors have elected to utilize public engagement by means of an anonymous survey as well as personal interactions with HIV advocates to synthesize paintings. Responses were collected from approximately 300 survey participants via social media with no demographic information collected. It was the hope of the authors that the lack of identifying questions may prompt participants to answer freely and honestly to improve overall understanding of social perceptions of HIV and its related stigma. These paintings and resources deemed appropriate based on the results of the aforementioned survey are to be displayed on a webpage for easier access and engagement with a broader audience.Moreover, this webpage is intended to be maintained and utilized beyond the timeframe of this Undergraduate Honors Thesis for the intended purpose of promoting stigma-free HIV advocacy and education.

Contributors

Agent

Created

Date Created
  • 2018-05

155408-Thumbnail Image.png

Prey-predator-parasite: an ecosystem model with fragile persistence

Description

Using a simple $SI$ infection model, I uncover the

overall dynamics of the system and how they depend on the incidence

function. I consider both an epidemic and endemic perspective of the

model,

Using a simple $SI$ infection model, I uncover the

overall dynamics of the system and how they depend on the incidence

function. I consider both an epidemic and endemic perspective of the

model, but in both cases, three classes of incidence

functions are identified.

In the epidemic form,

power incidences, where the infective portion $I^p$ has $p\in(0,1)$,

cause unconditional host extinction,

homogeneous incidences have host extinction for certain parameter constellations and

host survival for others, and upper density-dependent incidences

never cause host extinction. The case of non-extinction in upper

density-dependent

incidences extends to the case where a latent period is included.

Using data from experiments with rhanavirus and salamanders,

maximum likelihood estimates are applied to the data.

With these estimates,

I generate the corrected Akaike information criteria, which

reward a low likelihood and punish the use of more parameters.

This generates the Akaike weight, which is used to fit

parameters to the data, and determine which incidence functions

fit the data the best.

From an endemic perspective, I observe

that power incidences cause initial condition dependent host extinction for

some parameter constellations and global stability for others,

homogeneous incidences have host extinction for certain parameter constellations and

host survival for others, and upper density-dependent incidences

never cause host extinction.

The dynamics when the incidence function is homogeneous are deeply explored.

I expand the endemic considerations in the homogeneous case

by adding a predator into the model.

Using persistence theory, I show the conditions for the persistence of each of the

predator, prey, and parasite species. Potential dynamics of the system include parasite mediated

persistence of the predator, survival of the ecosystem at high initial predator levels and

ecosystem collapse at low initial predator levels, persistence of all three species, and much more.

Contributors

Agent

Created

Date Created
  • 2017

157117-Thumbnail Image.png

Prevalence rates of acute injection related injuries in a sample of persons who inject drugs in Phoenix, Arizona

Description

Opioid use in the United States is skyrocketing. Overdose deaths have increased 433% in

the last decade and will continue climbing. In addition to the mortality caused by illicit

opioid misuse, morbidity

Opioid use in the United States is skyrocketing. Overdose deaths have increased 433% in

the last decade and will continue climbing. In addition to the mortality caused by illicit

opioid misuse, morbidity rates have also risen. People Who Inject Drugs (PWID)

demonstrate higher rates of Human Immunodeficiency Virus (HIV), Hepatitis C Virus

(HCV), Endocarditis, Persistent Abscesses, Staphylococcus Aureus (S. aureus, Staph)

and other skin infections. This thesis serves as (1) a systematic review of the differences

in health conditions experienced by PWID and (2) an examination of the trends in skin

and soft tissue infection from a small sample in Phoenix, Arizona. The author argues that

PWID suffer from an increased rate of comorbid conditions associated with substance

use. Targeted social work interventions could be useful in reducing the rates of disease

and their impact on the individual and community.

Contributors

Agent

Created

Date Created
  • 2019

155092-Thumbnail Image.png

Persistence for "kill the winner" and nested infection Lotka-Volterra models

Description

In recent decades, marine ecologists have conducted extensive field work and experiments to understand the interactions between bacteria and bacteriophage (phage) in marine environments. This dissertation provides a detailed rigorous

In recent decades, marine ecologists have conducted extensive field work and experiments to understand the interactions between bacteria and bacteriophage (phage) in marine environments. This dissertation provides a detailed rigorous framework for gaining deeper insight into these interactions. Specific features of the dissertation include the design of a new deterministic Lotka-Volterra model with n + 1 bacteria, n
+ 1 phage, with explicit nutrient, where the jth phage strain infects the first j bacterial strains, a perfectly nested infection network (NIN). This system is subject to trade-off conditions on the life-history traits of both bacteria and phage given in an earlier study Jover et al. (2013). Sufficient conditions are provided to show that a bacteria-phage community of arbitrary size with NIN can arise through the succession of permanent subcommunities, by the successive addition of one new population. Using uniform persistence theory, this entire community is shown to be permanent (uniformly persistent), meaning that all populations ultimately survive.

It is shown that a modified version of the original NIN Lotka-Volterra model with implicit nutrient considered by Jover et al. (2013) is permanent. A new one-to-one infection network (OIN) is also considered where each bacterium is infected by only one phage, and that phage infects only that bacterium. This model does not use the trade-offs on phage infection range, and bacterium resistance to phage. The OIN model is shown to be permanent, and using Lyapunov function theory, coupled with LaSalle’s Invariance Principle, the unique coexistence equilibrium associated with the NIN is globally asymptotically stable provided that the inter- and intra-specific bacterial competition coefficients are equal across all bacteria.

Finally, the OIN model is extended to a “Kill the Winner” (KtW) Lotka-Volterra model

of marine communities consisting of bacteria, phage, and zooplankton. The zooplankton

acts as a super bacteriophage, which infects all bacteria. This model is shown to be permanent.

Contributors

Agent

Created

Date Created
  • 2016

151857-Thumbnail Image.png

MRI visualization and mathematical modeling of local drug delivery

Description

Controlled release formulations for local, in vivo drug delivery are of growing interest to device manufacturers, research scientists, and clinicians; however, most research characterizing controlled release formulations occurs in vitro

Controlled release formulations for local, in vivo drug delivery are of growing interest to device manufacturers, research scientists, and clinicians; however, most research characterizing controlled release formulations occurs in vitro because the spatial and temporal distribution of drug delivery is difficult to measure in vivo. In this work, in vivo magnetic resonance imaging (MRI) of local drug delivery is performed to visualize and quantify the time resolved distribution of MRI contrast agents. I find it is possible to visualize contrast agent distributions in near real time from local delivery vehicles using MRI. Three dimensional T1 maps are processed to produce in vivo concentration maps of contrast agent for individual animal models. The method for obtaining concentration maps is analyzed to estimate errors introduced at various steps in the process. The method is used to evaluate different controlled release vehicles, vehicle placement, and type of surgical wound in rabbits as a model for antimicrobial delivery to orthopaedic infection sites. I are able to see differences between all these factors; however, all images show that contrast agent remains fairly local to the wound site and do not distribute to tissues far from the implant in therapeutic concentrations. I also produce a mathematical model that investigates important mechanisms in the transport of antimicrobials in a wound environment. It is determined from both the images and the mathematical model that antimicrobial distribution in an orthopaedic wounds is dependent on both diffusive and convective mechanisms. Furthermore, I began development of MRI visible therapeutic agents to examine active drug distributions. I hypothesize that this work can be developed into a non-invasive, patient specific, clinical tool to evaluate the success of interventional procedures using local drug delivery vehicles.

Contributors

Agent

Created

Date Created
  • 2013

150131-Thumbnail Image.png

Use of random peptide reactivities to analyze host immune responses of African swine fever virus infection and immunization

Description

African Swine Fever (ASF), endemic in many African countries, is now spreading to other continents. Though ASF is capable of incurring serious economic losses in affected countries, no vaccine exists

African Swine Fever (ASF), endemic in many African countries, is now spreading to other continents. Though ASF is capable of incurring serious economic losses in affected countries, no vaccine exists to provide immunity to animals. Disease control relies largely on rapid diagnosis and the implementation of movement restrictions and strict eradication programs. Developing a scalable, accurate and low cost diagnostic for ASF will be of great help for the current situation. CIM's 10K random peptide microarray is a new high-throughput platform that allows systematic investigations of immune responses associated with disease and shows promise as a diagnostic tool. In this study, this new technology was applied to characterize the immune responses of ASF virus (ASFV) infections and immunizations. Six sets of sera from ASFV antigen immunized pigs, 6 sera from infected pigs and 20 sera samples from unexposed pigs were tested and analyzed statistically. Results show that both ASFV antigen immunized pigs and ASFV viral infected pigs can be distinguished from unexposed pigs. Since it appears that immune responses to other viral infections are also distinguishable on this platform, it holds the potential of being useful in developing a new ASF diagnostic. The ability of this platform to identify specific ASFV antibody epitopes was also explored. A subtle motif was found to be shared among a set of peptides displaying the highest reactivity for an antigen specific antibody. However, this motif does not seem to match with any antibody epitopes predicted by a linear antibody epitope prediction.

Contributors

Agent

Created

Date Created
  • 2011